Maria Shriver has filed for divorce from former California governor Arnold Schwarzenegger citing "irreconcilable differences."

Shriver and Schwarzenegger were married for 25 years and have four children ... Katherine, Christina, Patrick and Christopher.

The couple reportedly did not have a prenup. The papers also state Ms. Shriver, who is repped by attorney Laura Wasser, is asking for spousal support from the Terminator star.

Back in May, Schwarzenegger's affair with household employee Mildred Baena was revealed when the LA Times published a report claiming the actor had fathered a son ten years ago with a woman other than his wife Maria Shriver. Baena worked for the family for 20 years.